Basic HTML Version
CPU LED Indicator Codes Table
Diagnostic LED
Blinks'
CPU Problem
Explanation
Flashes
1
U25 RAM FAILURE U25 RAM could not be used properly (NO other tests are performed ;
the game Is locked here, until the game Is turned off).
2
MEM. PROT . FAILURE This message means that (A) the Coin Door
may
be shut; (8) the Mem-
ory Protect Switch may be stuck In the ON position; (C) the memory
protect logic Is protecting the memory; or (D) a U25 RAM failure Is
occurring. (See Note 1)
3
U51 PIA FAILURE
U51 has a malfunction . (See Note 2)
4
U38 PIA FAILURE
U38 has a malfunction. (See Note 2)
5
U41 PIA FAILURE
U41 has a malfunction. (See Note 2)
6
U42 PIA FAILURE
U42 has a malfunction. (See Note 2)
7
U54 PIA FAILURE
U54 has a malfunction. (See Note 2)
8
UtO PIA FAILURE
UtO has a malfunction. (See Note 2)
9
IRQ FAILURE
IRQ has a malfunction. It may be missing or too fast or too slow.
10
U27 ROM FAILURE U27's Internal checksums do not match. It may be a ROM failure, or Its
associated connections and connectlngdevlces are causing It to ap-
pear to have a problem. (The following U26 test Is Skipped.)
1 1
U26 ROM FAILURE U26's Internal checksums do not match.
Notes:
1. This test assumes that the Coin Door Is OPEN; It Is Initiated ONLY by pressing the CPU
Diagnostic Switch (SW2).
2. Alternatlvely,lts associated connections or connecting devices are causlng the IC to ap-
pear to have problems.
System 11-8 Sound Circuitry Tests
Tests of the System-lIB Sound Circuitry, including the Audio Board, are possible
only after successful completion of the System-lIB Memory Chip Test.
1. Audio Board Test. A brief check of the Audio Board (D-II58I) Circuitry
occurs at game Turn-on; the game reports the test results by brief sounds,
as follows: No sound
=
Audio Board is not operating, or a failure is
affecting the sound circuitry (broken cable; dead amplifier; etc.): I sound
=
system OK; 2 sounds
=
RAMproblem; 3 sounds
=
U4 problem; 4 sounds
=
UI9 problem.
2. General System-lIB Sound Test. Press the Sound Diagnostic Switch (SW 1)
on left edge of the CPU Board. L1sten for the two test sounds, showing that
both the CVSD (Continuously Variable Slope Delta) Modulator, which
provides the voices for
ELVIRA.
and the DAC (Digital-to-Analog
Converter) sound circuits are functioning properly.
If no sound is heard. refer to the text entitled "NOSOUND ...". If one "ring"
is heard, this indicates a malfunction of the U23 RAMChip. If either two or
four "rings" is heard, this indicates a problem associated with the U21 ROM
Chip. If either three or five "rings" is heard, this indicates a problem with
the U22 ROM Chip.
1-42 Test/Diagnostic Procedures